This invention relates to a dispensing nozzle of the type used for dispensing liquid fuels such as gasoline and the like. It is particularly directed to a compact, relatively inexpensive, and durable dispensing nozzle having a cast body, having improved hold-open means for latching a manually operated lever in an open position, and having improved automatic shut-off means.
Gasoline dispensing nozzles conventionally include a casing having an inlet and an outlet, an outlet spout, and a poppet valve for controlling flow between the inlet and outlet spout. The poppet is urged downwardly against its seat by a spring. A valve stem, which is operated by a manually operated lever or handle, extends into the poppet valve and opens the poppet valve against the force of the spring. The plunger of an automatic shut-off assembly forms a pivot for the lever at the forward end of the lever. The shut-off assembly also includes latching balls which are mounted in an upper portion of the plunger and are pushed outward by a latch pin against a ring carried by a shoulder in the casing. The latch pin includes a tapered surface which engages the balls. The latch pin is carried on one side of a diaphragm, the other side of which defines a pressure chamber with a cap on the body. A spring in the pressure chamber determines the sensitivity of the mechanism to changes in pressure in the pressure chamber. The latch pin is withdrawn from the plunger in response to submerging the end of the outlet spout in liquid. When the latch pin is withdrawn from the plunger, the balls move inward away from the shoulder; the plunger drops, thereby shifting the pivot point and preventing the lever from lifting the valve stem. This construction is well known in the art and is described in my U.S. Pat. No. 3,757,834, No. 4,378,824 and No. 4,487,238, the disclosures of which are hereby incorporated, and in Lawrence et al, U.S. Pat. No. 3,877,480, for example. The construction of the automatic shut-off mechanism requires great precision in the taper angle of the latch pin, the force of the pressure chamber spring, and the face of the ring against which the balls bear. The mechanism is therefore difficult to manufacture accurately and subject to failure with wear.
The automatic shut-off system of commercially available fuel dispensing nozzles drops the pivot point of the manual lever sufficiently to disable the lever from opening the nozzle's valve regardless of the position of the lever. Therefore, the lever may be held by a clip of some sort, to relieve the operator from holding the lever while a fuel tank is being filled. It has been recognized as desirable that the clip be simple, that it hold the lever securely, that it retract automatically when the automatic shut-off operates, so that the lever returns to its rest position, that it not obstruct the lever or the hand of the user in normal operation, and that it be operable with the same hand that is operating the lever. It is also desirable for the clip to be durable and relatively immune to environmental interference such as ice. The clip should also not protrude from the nozzle body or interfere with positioning the nozzle in a fuel tank or on a pump rack.
Various clips have been provided in the past, but none has met all of the foregoing criteria.